Dual Heteroatom-Doped Carbon Nanofoam-Wrapped Iron Monosulfide Nanoparticles: An Efficient Cathode Catalyst for Li-O-2 Batteries

Abstract

Cost-effective dual heteroatom-doped 3D carbon nanofoam-wrapped FeS nanoparticles (NPs), FeS-C, act as efficient bifunctional catalysts for Li–O2 batteries. This cathode exhibits a maximum deep discharge capacity of 14 777.5 mA h g−1 with a 98.1 % columbic efficiency at 0.1 mA cm−2. The controlled capacity (500 mA h g−1) test of this cathode delivers a minimum polarization gap of 0.73 V at 0.1 mA cm−2 and is sustained for 100 cycles with an energy efficiency of approximately 64 % (1st cycle) and 52 % (100th cycle) at 0.3 mA cm−2, under the potential window of 2.0–4.5 V. X-ray photoelectron spectroscopy reveals the substantial reversible formation and complete decomposition of Li2O2. The excellent recharging ability, high rate performance, and cycle stability of this catalyst is attributed to the synergistic effect of FeS catalytic behavior and textural properties of heteroatom-doped carbon nanostructures. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim